ABSTRACT
Dr. William Barclay made the above statement nearly 20 years ago in an editorial accompanying an article by Graham and Houston that investigated ascent to altitude by patients with chronic obstructive pulmonary disease (COPD) (2). Since then, more and more people with various medical conditions have been traveling to highaltitude areas for recreation or work, and many are choosing to live there, including older retirees. In response to the increased need for knowledge about how illness and altitude mix, the nascent literature is starting to grow. Overall, however, for many conditions, few conclusions can be drawn from the available work that will aid the clinician in advising his or her patients about their potential risks of ascent to high altitude. Hopefully, this attempt to present and critique this largely anecdotal literature will encourage scientists and clinicians to pursue further investigations, as Barclay beseeched. This chapter will focus on the available research, what conclu-
sions may or may not be drawn from these studies, and what important questions remain to be answered. The scope includes the effect of altitude on preexisting illnesses, the effect of illnesses on altitude acclimatization, and altitude effects on special states such as pregnancy and the elderly.
